The present invention relates to an optical encoder, as well as electronic equipment using the same, in which light emitted from a light emitting element is applied to a detection object and then light transmitted by the detection object or light reflected by the detection object is detected by a light receiving element.
Conventionally, JP 3-76428 B discloses an optical encoder in which with a light emitting element and a light receiving element provided, light from the light emitting element, passing through a slit, is detected by the light receiving element, and an optical signal detected by the light receiving element is converted into an electric signal, so that passing velocity and passing direction of the slit are determined based on the electric signal.
However, in the conventional optical encoder, an outer casing for fixing each of the light emitting element and the light receiving element and a lens for collimating light emitted from the light emitting element are provided by different component parts. This causes a problem that the number of component parts constituting the optical encoder increases, which causes a cost increase.
Also, if the lens is provided with a birefringence function or a lens aberration improvement function, the parts count increases accordingly, causing a further cost increase as another problem.
Furthermore, in the conventional optical encoder, light emitted from the light emitting element is collimated by the lens and passed through a dark-and-bright pattern provided by the slit so as to be detected by the light receiving element. However, there are some cases where the distance between the light emitting element and the light receiving element more or less differs from a reference value, or where the resolution more or less differs from a reference value, so that incidence characteristics of light onto the light receiving element becomes unstable because of the collimation of light, as a further problem.